Divided flow hairdryer

ABSTRACT

A hairdrying device having an electrically driven fan mounted therein for blowing ambient air, two distinct internal air flow paths which terminate at a common output orifice, in one of which is mounted an electric resistance heating element, and an air flow regulator movably disposed common to both paths and located adjacent the common output orifice for mixing the hot and cold air streams in a ratio, according to the user&#39;&#39;s desire, which is infinitely variable. The air flow regulator is in the form of a shutter which is larger than the output end of the air flow paths and has an open portion and a solid portion in which the open portion covers one of the paths and the solid portion covers the other in any desired ratio.

I United States Patent 1151 3,674,980 Cox 1 1 July 4, 1972 154] DIVIDED FLOW HAIRDRYER 1,751,841 3 1930 Pickens ..219/369 x 2,090,165 8/1937 Werner ..34/98 [72] Inventor Franc pome'and' Newcastle 2,914,648 11/1959 Allander ,...219/370 x Engmd 3,272,966 9/1966 Sutton 219/367 x [73] Assignee; Ronson (jol-porafion, woodbridge, 3,290,l 12 12/1966 Gillenwater et al... ...2l9/367 X 3,394,755 7/1968 Morrison 1 65/103 [22] Filed: May 9, 1968 Primary Examiner-A. Bartis [2]] App, 727'806 Att0rney-Marvin Trimas [30] Foreign Application Priority Data [5 7] ABSTRACT May 9, 1967 Great Britain ..2 l ,585/67 A hairdrying device having an electrically driven fan mounted therein for blowing ambient air, two distinct internal air flow [52] US, Cl ,219/367, 34/9134/243 paths which terminate at a common output orifice, in one of 165/103, 165/122, 219/368, 219/370 which is mounted an electric resistance heating element, and 51 Int. Cl .1105 3/00, F24h 3 04, A45d 20/08 an air flow regulator movably disposed Common to both Paths 53 Field ofSearch ,.2l9/366-371, 359, and located adjacent the Common Output Orifice for mixing 219/374-376 365 379-381- 165/103 121 122 the hot and cold air streams in a ratio, according to the user's 6 desire, which is infinitely variable. The air flow regulator is in the form ofa shutter which is larger than the output end of the {56' Reerences Cited air flow paths and has an open portion and a solid portion in which the open portion covers one of the paths and the solid U TE S T P EN S portion covers the other in any desired ratio. |,707,554 2/1929 Hendry .219/370 UX 10 Claims, 2 Drawing Figures DIVIDED FLOW HAIRDRYER BACKGROUND OF THE INVENTION 1 Field of Invention This invention relates to hairdryers and, in particular, to a hairdryer having a temperature variable output.

2. Description of the Prior Art In the hairdryer art, a variety of hairdryers having temperature variable outputs are known. In some of these devices, a switch is provided so that the heating element may be isolated to permit only cool air to be discharged from the hairdryer. This two-state output has not proven very satisfactory in operation since the cool state provided air too cool to accomplish the drying function and is, therefore, inefficient, while the hot stage provided heated air at elevated temperatures which, after a short period of operation, is uncomfortable and occasionally injurious to the user. Still other prior art devices achieve output temperature variation by altering the number of heater elements in the air flow circuit. This procedure necessitates the use of a high quality switch, which adds to the cost of the unit, yet makes available only a limited number of temperature ranges, usually to about four. In addition, cost analysis has shown that a significant proportion of production costs results directly from the inclusion of a variable heat feature of this type.

SUMMARY OF THE INVENTION The primary object of the present invention is to provide an improved hair dryer having a variable temperature output.

Another object of the present invention is to provide an improved hairdryer having a variable temperature output which is only slightly more expensive to manufacture than hairdryers not having a variable temperature output feature and less expensive to manufacture than hairdryers employing more sophisticated and costly variable temperature output means.

It is a further object of the present invention to provide an improved hairdryer having a variable temperature output which is as simple to operate as hairdryers which do not have a variable temperature output feature.

In accordance with the present invention, there is provided a hairdryer comprising a fan and a heater, the fan being arranged so that air driven thereby is centripitally forced along a deflector wall surrounding the fan and is divided between two paths, both of which terminate at a common output orifice, the air through one path only passing through or by the heater, and a movable shutter common to both paths being provided at the common output orifice, whereby adjustment of the shutter causes the output to comprise air from either path only, or air from both paths as a mixture in a ratio which is infinitely variable.

The invention permits infinite variation of output airflow temperature in a hairdryer in a low-cost and safe manner.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a plan view, of a hairdryer embodying the present invention.

FIG. 2 is a vertical sectional view taken through the plane 22 of the hairdryer shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2, an improved hairdryer according to the present invention is shown which comprises an outer housing 11 comprised of upper and lower mating segments equipped with a lead-in anchor 12 for an electrical supply cable 13 which is capable of connection to an external electrical source, not shown. Within the housing II, is mounted a motor 14 which has a vertically upwardly extending shaft 15. Upon the shaft 15 is mounted centrifugal impeller 16 which includes a hub 16a having six straight, radially-extending impeller blades 17, although any convenient number of blades can be employed. Deflector wall 18 shaped like the numeral 9," is positioned around the impeller 16 and arcuately extends along the lower portion of the housing ll, terminating at the output orifice 19 (more clearly shown in FIG. 2). Air is drawn into the hairdryer by the impeller 16 via an input orifice in the housing (not shown) located adjacent the impeller 16 and forced around the interior of the deflector wall 18. Sagittal lines 20 and 21 indicate the flow pattern of air leaving the impeller and show, in a manner to be hereinafter described, how the air is divided into two paths, only one of which includes a heater 22.

The heater 22 is housed within an open-ended, box-like assembly, generally indicated by the numeral 23, having side walls 24 and 25. The side walls 24 and 25 are formed from a heat resistant and electrical insulating material for safety purposes and for locally restricting the heating effect of the heater 22. The inner surfaces 26 and 27, of side walls 24 and 25, in cooperation with the contiguous portions of the top and bottom segments of the housing ll, define the path for the heated air, as indicated by sagittal line 20. The outer surface 28 of side wall 25 and the lower extending portion of deflector wall 18, in cooperation with the contiguous portions of the top and bottom segments of the housing 11, define the path for the cool air, as indicated by sagittal line 21.

The motor 14 and the heater 22 are connected by suitable wiring 29. A rotatable control knob 30 is used to operate, in known manner, a set of switch contacts, not shown, by which the motor 14 may be energized and the heater 22 connected in circuit. A T-shaped shutter 32 (more clearly shown in FIG. 2) has a leg 33 which is provided with a rack gear 34, and a head 35. The head 35 comprises a sold section and a slotted section. The rack gear 34 engages the pinion 36 carried on and fixed to the shah 31 of the control knob 30. Rotation of the control knob 30 causes the shutter head 35 to move in guides 37 formed in the housing ll. The shutter head 35 itself is large enough to cover the output orifice or exit end of the hot and cold air paths simultaneously and has a number of openings 38 which can be of any desired shape cut in its upper half just below the shutter leg 33. Thus, with the shutter head 35 in a position to close the cold air path, its slotted half is opposite the hot air path, thereby permitting only the flow of heated air from the orifice 19.

The shutter 32 carries an extension 39 which is formed from the same sheet as the shutter 32, but is bent so as to extend at a right angle to the plane of the shutter 32. The extension 39 cooperates with an opening 40 in the housing 11 which opening communicates with the path containing the heating element to insure that sutficient air may pass therethrough to prevent overheating when the hot air path is blocked by the solid section of the shutter head 35. The shutter 32 in FIG. 2 is shown in a position in which the hot air path is completely closed so that only cold air is being delivered from the hairdryer. In this position, the opening 40 is not covered by the shutter extension 39 so that, although the heated air no longer exits from the hairdryer at the orifice 19, there is sufficient air passing out to the atmosphere by way of opening 40 to prevent the heater from being damaged.

When the control knob 30 is rotated by the user in a clockwise direction, the shutter 32 will be caused to move to the user's left, or downwardly as in FIGS. 1 and 2, progressively closing the cold air path and simultaneously opening the hot air path until finally, at the end of its travel, the cold air path will be closed and the hot air path fully open. The control knob 30 may, of course, be stopped at any point between the two extreme positions so that any ratio of cold to hot air may be available at the output orifice 19 so that effective temperature is similarly variable.

The type of hairdryer to which the present invention is par ticularly applicable utilizes a flexible hose which conveys the air from the hairdryer to a hood or hand-held adaptor for drying the hair. The hose in this type of hair dryer acts as a mixing chamber so that the temperature of the drying air is uniform at the intermediate settings of the shutter 32, whereas without the hose there may be a tendency to have an air flow which is stratified at different temperatures.

Having shown and described in the drawings and specification the preferred embodiment of the present invention, it is nevertheless to be understood that various changes thereto may be made without departing from the spirit and scope of the invention as set forth in the following claims:

I claim:

I. A hairdryer which comprises:

a a housing having an input orifice and an output orifice;

b. driving means mounted within the housing;

c. air moving means connected to the driving means and located adjacent the input orifice;

d. walls mounted within the housing, surrounding the air moving means defining a first and a second path, the paths extending from adjacent the air moving means to adjacent the output orifice;

e. a heating element mounted within one of the paths for heating air passing therethrough;

f. a shutter, greater in size than the output orifice end of the paths, movably mounted within the housing in slidable engagement with the output orifice end of the paths and having an open portion and a solid portion;

1. the open portion covering one of the paths and the solid portion covering the other path at one extreme of shutter travel; and

2. the solid portion covering the path formerly covered by the open portion of the shutter at the other extreme of shutter travel;

g. means for energizing the driving means and the heating element; and

h. actuating means for selectively moving the shutter from one extreme of its travel to the other extreme or to any intermediate position of travel. A hairdryer according to claim 1 wherein:

the shutter has a rack gear formed at one end thereof; and the actuating means comprises: 1. a control knob rotatably mounted on the housing having a shaft extending into the housing; and 2. a pinion mounted on the shaft in meshing engagement with the rack gear. A hairdryer according to claim 1 wherein: the housing has an opening communicating with the path containing the heating element; and

b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element.

4. A hairdryer according to claim 3 wherein:

a. the shutter has a rack gear formed at one end thereof; and

b. the actuating means comprises:

l. a control knob rotatably mounted on the housing having a shaft extending into the housing; and

2. a pinion mounted on the shaft in meshing engagement with the rack.

5. A hairdryer according to claim 1 wherein the walls further comprise:

a. a deflector wall formed in the shape of the numeral 9,

mounted in the housing;

1. the circular portion thereof being partially open and surrounding the air moving means; and

2. the tail portion thereof extending to adjacent the output orifice;

b. a first side wall mounted within the housing substantially parallel to the tail portion of the deflector wall and extending from adjacent the beginning of the curved portion of the deflector wall to adjacent the output orifice;

c. a second side wall mounted within the housing, substantially parallel to the tail portion of the deflector wall, between the first side wall and the deflector wall and extending from adjacent the opening of the curved portion of the deflector wall to adjacent the output orifice to define the first path and the second path, which paths receive the air flow centripitally forced It? the air movin means around the interior 0 the de ector wall ans through the opening in the curved portion thereof. 6. A hairdryer according to claim 5 wherein: a. the shutter has a rack gear formed at one end thereof; and b. the actuating means comprises;

1. a control knob rotatably mounted on the housing having a shaft extending into the housing; and

2. a pinion mounted on the shaft in meshing engagement with the rack gear.

7. A hairdryer according to claim 5 wherein:

a. the housing has an opening communicating with the path containing the heating element; and

b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element.

8. A hairdryer according to claim 7 wherein:

a. the shutter has a rack gear formed at one end thereof; and

b. the actuating means comprises:

1. a control knob rotatably mounted on the housing having a shaft extending into the housing; and

2. a pinion mounted on the shaft in meshing engagement with the rack gear.

9. A hairdryer according to claim I which further comprises:

a. a guide formed in the housing adjacent to the output orifice end of the paths; and in which b. the shutter is T-shaped and movably mounted in the guide;

l. the head section of the shutter being of greater size than the output orifice end of the paths and comprising an open portion and a solid portion; and

2. the leg section of the shutter having a rack gear formed thereupon;

c. a control knob rotatably mounted on the housing having a shaft extending into the housing; and

d. a pinion mounted on the shaft of the control knob in meshing engagement with the rack gear so that rotation of the control knob will cause the shutter to be slidably and selectively moved from one extreme of its travel to the other extreme or to any intermediate position of travel.

10. A hairdryer according to claim 9 wherein:

a. the housing has an opening communicating with the path containing the heating element; and

b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element. 

1. A hairdryer which comprises: a a housing having an input orifice and an output orifice; b. driving means mounted within the housing; c. air moving means connected to the driving means and located adjacent the input orifice; d. walls mounted within the housing, surrounding the air moving means defining a first and a second path, the paths extending from adjacent the air moving means to adjacent the output orifice; e. a heating element mounted within one of the paths for heating air passing therethrough; f. a shutter, greater in size than the output orifice end of the paths, movably mounted within the housing in slidable engagement with the output orifice end of the paths and having an open portion and a solid portion;
 1. the open portion covering one of the paths and the solid portion covering the other path at one extreme of shutter travel; and
 2. the solid portion covering the path formerly covered by the open portion of the shutter at the other extreme of shutter travel; g. means for energizing the driving means and the heating element; and h. actuating means for selectively moving the shutter from one extreme of its travel to the other extreme or to any intermediate position of travel.
 2. the solid portion covering the path formerly covered by the open portion of the shutter at the other extreme of shutter travel; g. means for energizing the driving means and the heating element; and h. actuating means for selectively moving the shutter from one extreme of its travel to the other extreme or to any intermediate position of travel.
 2. A hairdryer according to claim 1 wherein: a. the shutter has a rack gear formed at one end thereof; and b. the actuating means comprises:
 2. a pinion mounted on the shaft in meshing engagement with the rack gear.
 2. a pinion mounted on the shaft in meshing engagement with the rack.
 2. the tail portion thereof extending to adjacent the output orifice; b. a first side wall mounted within the housing substantially parallel to the tail portion of the deflector wall and extending from adjacent the beginning of the curved portion of the deflector wall to adjacent the output orifice; c. a second side wall mounted within the housing, substantially parallel to the tail portion of the deflector wall, between the first side wall and the deflector wall and extending from adjacent the opening of the curved portion of the deflector wall to adjacent the output orifice to define the first path and the second path, which paths receive the air flow centripitally forced by the air moving means around the interior of the deflector wall and through the opening in the curved portion thereof.
 2. a pinion mounted on the shaft in meshing engagement with the rack gear.
 2. a pinion mounted on the shaft in meshing engagement with the rack gear.
 2. the leg section of the shutter having a rack gear formed thereupon; c. a control knob rotatably mounted on the housing having a shaft extending into the housing; and d. a pinion mounted on the shaft of the control knob in meshing engagement with the rack gear so that rotation of the control knob will cause the shutter to be slidably and selectively moved from one extreme of its travel to the other extreme or to any intermediate position of travel.
 3. A hairdryer according to claim 1 wherein: a. the housing has an opening communicating with the path containing the heating element; and b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element.
 4. A hairdryer according to claim 3 wherein: a. the sHutter has a rack gear formed at one end thereof; and b. the actuating means comprises:
 5. A hairdryer according to claim 1 wherein the walls further comprise: a. a deflector wall formed in the shape of the numeral ''''9,'''' mounted in the housing;
 6. A hairdryer according to claim 5 wherein: a. the shutter has a rack gear formed at one end thereof; and b. the actuating means comprises;
 7. A hairdryer according to claim 5 wherein: a. the housing has an opening communicating with the path containing the heating element; and b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element.
 8. A hairdryer according to claim 7 wherein: a. the shutter has a rack gear formed at one end thereof; and b. the actuating means comprises:
 9. A hairdryer according to claim 1 which further comprises: a. a guide formed in the housing adjacent to the output orifice end of the paths; and in which b. the shutter is T-shaped and movably mounted in the guide;
 10. A hairdryer according to claim 9 wherein: a. the housing has an opening communicating with the path containing the heating element; and b. the shutter has an extension mounted thereupon which seals the opening when the open portion of the shutter covers the path containing the heater element and leaves the opening fully uncovered when the solid portion of the shutter covers the path containing the heating element. 